1. Field of the Invention
The present invention generally relates to a harness connector assembly comprising plug and socket connectors adapted to be electrically connected together in a plug-in fashion. More particularly, the present invention relates to one of the plug and socket connectors of a type wherein at least one pair of electrical contacts are short-circuited by means of a contact bridge before use, that is, before the other of the plug and socket connectors is inserted into such one of the plug and socket connectors to establish an electrical connection therebetween.
2. Description of the Prior Art
In an automobile, for example, electric wires used to distribute electric power among numerous electrically operated devices are bound together into harnesses. Those electric wires bound together into the harnesses are generally known as wiring harnesses and are generally marked by means of colors for identification purpose. The electric wires forming the wiring harness may lead out from an electrically operated device and terminate in a terminal connector, for example, a plug connector for connection with an electrical power source or a different electrically operated device through another similar wiring harness having a mating terminal connector, that is, a socket connector, at its opposite ends.
To establish an electrical harness-to-harness connection, it is a general practice to employ a plug-in connector assembly comprising a plug connector having a plurality of terminal pins and a socket connector having a corresponding number of terminal sockets for receiving the terminal pins. Of the variety of plug-in connector assemblies now in use, there is known a plug-in connector assembly of a design wherein one of the plug and socket connectors has at least one pair of the electrical contacts short-circuited by means of a contact bridge before use. In this design, the contact bridge short-circuited the electrical contacts in one connector is released, when the other connector is inserted into such one connector, to isolate the electrical contacts from each other while allowing them to be electrically connected with associated electrical contacts in the other connector. The plug-in connector assembly of the above discussed design is generally used in, inter alia, an automobile security circuit associated with a security air bag for inflating the air bag in the event of an automobile accident.
For example, the Japanese Laid-open Utility Model Publications No. 64-41989, published Mar. 13, 1989, and No. 1-77287, published May 24, 1989, reproduced in FIGS. 10 and 11 of the accompanying drawings, respectively, disclose the socket connector including two electrical contacts short-circuited by a releasable contact bridge within a socket housing.
More specifically, the plug-in connector assembly disclosed in the first mentioned publication No. 64-41989 and reproduced in FIG. 10 comprises a socket connector including two generally tubular socket contacts 5 within a generally rectangular socket housing 1, and a plug connector including an equal number of elongated plug contacts 6 within an openended plug housing 2 adapted to receive therein the socket housing 1 with the plug contacts 6 plugged into the socket contacts 5. As shown therein, each of the socket contacts 5 has an elastically yieldable tongue 8 formed integrally therewith so as to extend in a direction counter to the direction of insertion of the socket contacts 5 into the socket housing 1. A generally rectangular contact bridge 4 is secured to an inner surface of a top wall of the socket housing 1 so as to lie in a direction perpendicular to the direction of insertion of the socket contacts 5 into the socket housing 1 and also to the longitudinal axes of the socket contacts 5.
In assembling the socket connector, the socket contacts 5 are press-fitted into the socket housing 1 one at a time so as to extend parallel to each other. At this time, the elastically yieldable tongues 8 are, during the insertion of the socket contact 5 into the socket housing 1, elastically yielded inwardly while accumulating an outwardly acting elastic force, and then expand outwardly upon completion of the insertion by the action of the accumulated outwardly acting elastic force. In an assembled condition shown in FIG. 10, the elastically yieldable tongues 8 are held in contact with the contact bridge 4 thereby to establish an electric circuit between the socket contacts 5 within the socket housing 1.
The electric circuit between the socket contacts 5 can be opened when the plug contacts 6 within the plug connector are inserted into the socket contacts 5 with the socket housing 1 received within the plug housing 2. This is possible because, as the plug contacts 6 are inserted into the socket contacts 5, the elastically yieldable tongues 8, then expanded outwardly to engage the contact bridge 4, are inwardly yielded in contact with the plug contacts 6 to disengage from the contact bridge 4.
The plug-in connector assembly shown in FIG. 10 may work satisfactory in the electric circuit in which it is installed. However, the assemblage requires enough complicated and time-consuming procedures to make the plug-in connector assembly expensive to manufacture. Specifically, when the socket contacts 5 are inserted into the socket housing 1, the accumulated outwardly acting elastic force of each of the tongues 8 hampers a smooth insertion of the respective socket contact 5 into the socket housing 1. Therefore, it often occurs that the socket contact 5 is inserted halfway within the socket housing 1, and this is particularly true where the socket housing 1 has protuberances protruding into passageways through which the socket contacts 5 are inserted one at a time.
Also, before the socket contacts 5 are inserted into the socket housing 1, each tongue 8 remains outwardly protruding from the body of the associated socket contact and, therefore, it may often occur that the tongue 8 is detrimentally deformed during a transportation of the socket contacts before the assemblage or during the insertion thereof into the socket housing 1. In addition, because of the unique shape of each socket contact 5, the use thereof is exclusively limited to the particular type of plug-in connector assembly, thereby lacking a versatility.
Moreover, in order for the contact bridge 4 to be properly positioned within the socket housing 1, either the insert-molding process or the press-fitting technique has to be adopted to place the contact bridge 5 in position within the socket housing 1 and this leads to a reduction in work efficiency in installing the contact bridge 5.
On the other hand, the second mentioned publication No. 1-77287 discloses, as shown in FIG. 11, the use of the bridge contact 4 of a design having a pair of elastically yieldable, curled tongues 4a formed integrally therewith, instead of the elastic tongues 8 integral with the socket contacts 5 shown in FIG. 10. The contact bridge 4 is secured to an inner surface of a top wall of the socket housing 1 with the curled tongues 4a held in position ready to contact the socket contacts 5 when the latter are completely inserted into the socket housing 1.
The curled tongues 4a integral with the contact bridge 4 is cooperable with a generally rectangular insulating plate 7 disposed within or formed integrally with the plug housing 2 so as to lie above the elongated plug contacts 6 and at a location where, when the socket housing 1 is inserted into the plug housing 2 with the plug contacts 6 received within the respective socket contacts 5, the insulating plate is wedged in between the curled tongues 4a and the socket contacts 5 to separate the curled tongues 4a away from the socket contacts 5.
The socket connector shown in FIG. 11 has problems similar to those discussed in connection with the socket connector shown in FIG. 10.